A controlled study is a study or trial where two groups are used for comparison purposes. The higher the numbers the more significant the findings are. Clients are always asking us if certain drugs or herbal medicines are effective. If there are no controlled studies done on the drug we can’t really answer.

The other day someone asked me if feeding green beans to dogs makes them feel full without gaining weight. I really don’t know the answer to that question. I do know that there are special diets available from Hills and Royal Canin that are proven to make dogs feel satisfied and increase their metabolism so that they lose weight. There are controlled studies to prove this. Lots of herbs and essential oils are supposed to help cure certain ailments but without controlled studies proving their worth we can’t really recommend them. Milk thistle is now known to be good for the liver and certain milk proteins can calm animals down. These are commercially available and there are treats to help with liver disease and to calm dogs down.

Some horse people give their horsesfenbendazole for 5 days in a row to try to eliminate encysted small strongyles. You can deworm a horse and kill the adult worms but the encysted small stronglyes will then emerge and the horse is full of worms soon after. Products that kill adults and larvae are desirable. I really wondered about this 5 day Panacur regime as small strongyles are supposed to be resistant to fenbendazole (Panacur). I tried to find out where this idea came from and called an American Vet who was promoting this idea. He did not tell me much other than that it worked. It’s totally amazing how scientifically unproven things catch on in the horse world.

Well, someone in the states has done a controlled study finally. They took 120 mares from 21 states living on one farm. They did fecal egg counts on them all and divided the ones with over 200 eggs/gram in half. There were 41 horses in each group. Interestingly 38 horses had low egg counts. One group got treated with moxidectin or Quest which is the longest acting dewormer we have and it’s supposed to kill adults and larvae. The other group got the 5-day course of Panacur.

They checked the fecal egg counts at 14, 45 and 90 days post treatment. There was 99.9% fecal egg reduction at 14 days in the Quest treated group and only 41.9% in the Panacur group. By 45 days the fecal egg counts exceeded pre-treatment levels for the Panacur group but the Quest group fecal egg counts stayed below pre-treatment levels for 90 days. You have to give 50ml of Panacur daily for 5 days. That is not that easy to do.

They concluded from the study that there is widespread resistance to fenbendazole in cyathastomes and that moxidectin or Quest still works to kill adult and larval small strongyles. Another weird treatment people do is to give Quest dewormer, then the 5 days of Panacur and another Quest. This is problably severe overkill and the Panacur does not work well anyway. I am glad someone did a controlled study on this!!!!

Another myth I have heard since I moved here is that you should deworm horses on a full moon. They certainly did not teach us that in veterinary school. I will not pass judgement until I see a controlled study on full moon deworming which probably won’t be any time soon.